Immunization is one of the most significant public health achievements of the 20th century. Mass immunization has led to dramatic declines in vaccine-preventable diseases. Vaccines currently prevent more than 2 million deaths per year worldwide. However, as vaccine preventable diseases continue to decline, the focus of public concern has shifted from disease transmission to vaccine safety. Many parents in developed countries now believe the risks of vaccines outweigh the benefits. Some of these concerned parents choose to either decline or delay immunizations for their children. Research has shown that parents who decline or delay immunizations place their children at greatly increased risk for pertussis, varicella, and measles infection. Research also demonstrates that vaccine-hesitant parents use the internet to obtain information on vaccines. Much of this information, however, is inaccurate and biased. Effective intervention strategies to reduce parental concerns about immunizations are needed. The objective of this proposed research study is to develop and evaluate an interactive, social media website for parents who are concerned about vaccines. The website will feature various social media applications, including a blog, a discussion forum, and a social networking service. The website will also be a resource for providers who are interested in obtaining information about the newest vaccine-related concerns or discussing vaccine-related topics with parents. For this investigation, the website will be available to Kaiser Permanente Colorado (KPCO) patients and KPCO physicians. It will be moderated by physicians and vaccine researchers at the KPCO Institute for Health Research (IHR). At present, data on the relative benefit of using professionally moderated social media to influence health outcomes are lacking. This proposed pilot investigation will help inform future research to implement a larger, integrated behavioral health intervention to reduce parental concerns about vaccinations and increase immunization rates over time. PUBLIC HEALTH RELEVANCE: Project Narrative An increasing number of parents are concerned about vaccinating their children. Many parents receive false information about vaccinations from the internet. We propose an interactive social media website that provides a forum in which parents can access truthful, unbiased information and discuss vaccine-related issues with other parents and pediatricians.